BORROWINGS, Contractual Maturity on Borrowings (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Debt Instruments [Abstract]
Carrying value	$ 413,682	$ 485,896
Weighted-average rate	1.84%
Weighted-average interest rate on borrowings during period	1.72%	1.51%
January 2, 2019 [Member]
Debt Instruments [Abstract]
Carrying value	$ 313,767
Weighted-average rate	1.01%
July 3, 2023 [Member]
Debt Instruments [Abstract]
Carrying value	$ 575
Weighted-average rate	2.25%
October 23, 2023 [Member]
Debt Instruments [Abstract]
Carrying value	$ 484
Weighted-average rate	1.50%
October 1, 2025 [Member]
Debt Instruments [Abstract]
Carrying value	$ 315
Weighted-average rate	1.50%
March 1, 2029 [Member]
Debt Instruments [Abstract]
Carrying value	$ 602
Weighted-average rate	2.50%
December 15, 2034 [Member]
Debt Instruments [Abstract]
Carrying value	$ 20,619
Weighted-average rate	4.74%
December 15, 2036 [Member]
Debt Instruments [Abstract]
Carrying value	$ 77,320
Weighted-average rate	4.44%